'''Conway's Game Of Life, Author Anurag Kumar(mailto:anuragkumarak95@gmail.com) 

Requirements:
  - numpy
  - random
  - time
  - matplotlib

Python:
  - 3.5

Usage:
  - $python3 game_o_life <canvas_size:int>

Game-Of-Life Rules:
 
 1.
 Any live cell with fewer than two live neighbours
 dies, as if caused by under-population.
 2.
 Any live cell with two or three live neighbours lives
 on to the next generation.
 3.
 Any live cell with more than three live neighbours
 dies, as if by over-population.
 4.
 Any dead cell with exactly three live neighbours be-
 comes a live cell, as if by reproduction.
 '''
import random
import sys

import numpy as np

from matplotlib import use as mpluse
mpluse('TkAgg')
from matplotlib import pyplot as plt
from matplotlib.colors import ListedColormap

usage_doc = 'Usage of script: script_nama <size_of_canvas:int>'

choice = [0] * 100 + [1] * 10
random.shuffle(choice)


def create_canvas(size):
    canvas = [[False for i in range(size)] for j in range(size)]
    return canvas


def seed(canvas):
    for i, row in enumerate(canvas):
        for j, _ in enumerate(row):
            canvas[i][j] = bool(random.getrandbits(1))


def run(canvas):
    ''' This  function runs the rules of game through all points, and changes their status accordingly.(in the same canvas)
    @Args:
    --
    canvas : canvas of population to run the rules on.

    @returns:
    --
    None
    '''
    canvas = np.array(canvas)
    next_gen_canvas = np.array(create_canvas(canvas.shape[0]))
    for r, row in enumerate(canvas):
        for c, pt in enumerate(row):
            # print(r-1,r+2,c-1,c+2)
            next_gen_canvas[r][c] = __judge_point(pt, canvas[r - 1:r + 2, c - 1:c + 2])

    canvas = next_gen_canvas
    del next_gen_canvas  # cleaning memory as we move on.
    return canvas.tolist()


def __judge_point(pt, neighbours):
    dead = 0
    alive = 0
    # finding dead or alive neighbours count.
    for i in neighbours:
        for status in i:
            if status:
                alive += 1
            else:
                dead += 1

    # handling duplicate entry for focus pt.
    if pt:
        alive -= 1
    else:
        dead -= 1

    # running the rules of game here.
    state = pt
    if pt:
        if alive < 2:
            state = False
        elif alive == 2 or alive == 3:
            state = True
        elif alive > 3:
            state = False
    else:
        if alive == 3:
            state = True

    return state


if __name__ == '__main__':
    if len(sys.argv) != 2: raise Exception(usage_doc)

    canvas_size = int(sys.argv[1])
    # main working structure of this module.
    c = create_canvas(canvas_size)
    seed(c)
    fig, ax = plt.subplots()
    fig.show()
    cmap = ListedColormap(['w', 'k'])
    try:
        while True:
            c = run(c)
            ax.matshow(c, cmap=cmap)
            fig.canvas.draw()
            ax.cla()
    except KeyboardInterrupt:
        # do nothing.
        pass
